High pressure steam generator



May 28, 1940. o. SWIETOCHOWSKI 2,202,507

. HIGH PRESSURE STEAM GENERATOR Filed Oct. 9, 1955 2 Sheets-Sheet 1 iievezaiart oui/IER swmocnowsm AitOTZ'LGy S May 28, 1940. o. SWIETOCHOWSKI2,202,507

I HIGH PRESSURE STEAM GENERATOR I Filed Oct. 9, 1935 v 2 Sheets-Sheet 2Patented May 28, 1940 UNITED STATES V 2.202.507 HIGH PRESSURE STEAMGENERATOR Olivier Swietochowski, Mahrisch-strau', Protectorate Moraviaand Bohemia, former Czechoslovakia Application October 9, 1935, SerialNo. 44,171

In Germany October 13, 1934 9 Claims. (01. 122%31) This inventionrelates to high pressure steam boilers with indirect generation of steamby means of superheated steam which is withdrawn by means of a pump froman unheated boiler drum, is conveyed in a positive mannerthrough thesuperheaters andis thereupon blown in circulation into the water spaceof the boiler drum.

In theknown constructional forms of these steam generators, moreparticularly known as Lofiler boilers, the useful steam is alwayssuperheated in common superheaters together with the steam circulatingas the heat carrier and to the same temperature as the latter. It hasalso already been proposed to withdraw the useful steam from anintermediate stage of the common superheater and therefore to convey itto the points of consumption at a lower temperature,

than that of the circulating steam. This method was based on theprevailing assumption that go, the superheat temperature of the steamacting as the heat carrier should be driven as high as possible. It hasalso'already been proposed to limit the positive circulation to thesteam acting as the heat carrier by withdrawing the useful steamdirectly from the boiler drums and superheating it separately from thecirculating steam. In contradistinction thereto the invention consistsin withdrawing the useful steam in the known mannerby means of thecirculattozing pump, together with the circulating steam from the boilerdrum, and conveying it in a positive manner to the superheaters, then towithdrawing it' from the circulatory system after the partial orcomplete superheating of the circulat- -5iing steam and superheating itseparately from the circulating steam to a higher temperature than thelatter. In the case of boilers with radiation and convectionsuperheaters disposed with the latter in series after the first, theuseful -3, steam should preferably not be withdrawn before leaving theradiation superheater. This construction of steam circulating boilers isparticularly suitable for obtaining very high superheating temperaturesand for maintaining a lower- 455,1DOW6I' demand for the steamcirculation than would be necessary, when superheating the circulatingsteam to the-same high temperature as that of the useful steam. Thisarrangement also makes it possible to limit the employment 5030f highheat resistance material to the final superheater for the useful steam.Furthermore, the invention provides generally a greater freedom in thedistribution of the heat to be absorbed from the flue gases to thesundries, i. e.

55,;the superheating, of vthe steam, the preheating of the feed waterand the heating of the air and of the delivery of heat to the heating byradiation and'to the heating by contact with the flue gases.

- The invention is illustrated by way of example 5 in the annexeddrawings of which v Fig. 1 shows a diagrammatic View of a Loefilerboiler plant and a Fig. 2 a further modification of same.

According to the embodiment of the inven- 10 tion shown in Fig. 1 thecirculating pump 2 withdraws saturated steam from the boiler drum l andconveys it in a positive manner to the radia tion superheater '3 andthen to the convection superheater 4 which is heated by contact with theflue gases. 'After the convection-superheater 4 the useful steam iswithdrawn from the circulatory system at 5 and is superheated in thefinal superheater 6 to the temperature required at the points ofconsumption, for instance the turbo generator 0, While the steamcirculating as the heat carrier remains at the lower temperature at thepoint where it leaves the com Veotion-superheater 4 and is conveyed atthis temperature through, the pipes 1 and 8 to the boiler drum I, intothe water space of which it is then blown for the purpose of generatingsteam.

The final superheater 6 is preferably so arranged that it is heated onlyby contact with the fluegases. This is eifectedwith'advantage in aregion of lower flue gas temperatures. In the example illustrated theconvection-superheater 4 is divided into two sections connected inseries with one another, of which, that which is first swept through bythe steam is sweptover by the fiue gases directly after they leave thecombustion chamber and is arranged with the media flowing-in the samedirection, and the final superheater 6 which is also swept through bythe steam in the same direction as the flue gases is disposed betweenthese two sections of the convection-superheater 4. The second sectionof the convection-superheater 4 can then with advantage be connected upin counterflow with respect to the flue gases.

The final superheater 6 is preferably designed for relatively high steamvelocities, more 'particularly whenit is a question of producing verhigh superheating'temperatures. Y

For protecting the final superheater G apipe 9 having a valve 10 isprovided, which, when valve I0 is opened connects the outlet of thefinal superheater 8 at H with the pipe 8, which leads the circulatingsteamto the boiler drum l, a further valve [2 being provided in thecirculating pipe 1. This makes it possible to connect up the finalsuperheater 6 behind the con vection-superheater i in the circulatingsystem, when no steam is being withdrawn, when starting up and whenshutting off the boiler and so on, so that the entire superheaterheating surface can be swept over in a positive manner by the entireamount of steam conveyed by the steam circulating pump 2.

For protecting the final superheater ii there is also connected behindthe final superheater 3 the outlet valve it, which can be operatedautomatically or by hand in the case of danger, and the safety valve isfor blowing-off steam into the atmosphere. The amount of steam which hasto be blown off for avoiding inadmissible pressure and temperatureincreases can be kept low by at the same time connecting up the finalsuperheater 8 in the steam circulatory system.

For starting up and the like a short circuiting pipe i5 with a valve itis provided in front of the final superheater ii, so that the totalamount of conveyed steam need not be allowed to flow through the finalsuperheat'er E, but only as much steam as is necessary for ensuring thecooling of the final superheater ii.

For regulating the superheating temperature of the useful steam duringoperation saturated steam may be mixed with it at the inlet into thefinal superheater S. The saturated steam is Withdrawn behind thecirculating pump 2 at ll and is conveyed through the pipe is with theregulating valve E9 to the mixing nozzle 28. The valve is is controlledaccording to the final temperature of the useful steam by the thermostat2!, as is indicated by the impulse pipe 22.

The final superheating of the useful steam can also be regulated bymeans of the steam circulating pump 2 by varying the quantity of steamcirculated.

In the flow of flue gases, the course of which is indicated by arrows,there is disposed in the usual way behind the. convection-superheater ian economiser 23 and an air heater According to the embodiment of theinvention shown in Fig. 2 the circulating pump 2 withdraws saturatedsteam from the boiler drum l and delivers the same to the radiationsuperheater 3 and then to the convection superheater which consists oftwo sections 6 and *3. Useful steam is withdrawn from the convectionsuperheater at 5 and is further superheated in the supe heater 8 to therequired final temperature.

In order to protect the final superheater 5 a pipe 9 with valve it isprovided which when valve H) is opened connects the superheater 6 at Hwith the pipe 8 which leads the circulating steam to the boiler drum 4 afurther valve 12 being provided in the circulating pipe '7.

For further protection of the superheater 8 there is also connectedbehind the final superheater 6 the outlet valve it, which can beoperated automatically or by hand in the case of danger, and the safetyvalve it for blowing-off steam into the atmosphere.

In order to further connect the superheater with the circulatory systema pipe is provided which connects the outlet of said superheater 4 and 4at H with the inlet of the superheater 6; a valve I2 is located in thispipe 1' and a valve 12 is located between the withdrawal point 5 of theuseful steam and the inlet in superheater 6. v

The steam which passes from the boiler drum I through the circulatingpump 2 and through the radiation superheater 3 enters section 4 of theconvection superheater. A portion of the circulating steam, is withdrawnat 5; it flows through the mixing nozzle 20 and to the pipe 7 leading tothe superheater 8 where it is superheated to the temperature required atthe point of consumption f. i. the turbo-generator V. The circulatingsteam is conveyed through the other section 4 of the convectionsuperheater and through pipes l and 8 into the water space of the boilerdrum i.

For starting up and the like a short circuiting pipe 5 with a valve itis provided in front of the final superheater '6, so that the totalamount of conveyed steam need not be allowed to flow through the finalsuperheat'er B, but only as much steam as is necessary for ensuring thecooling of the final superheater 6.

For regulating the superheating temperature of the useful steam duringoperation saturated steam may be mixed withit at the inlet into thefinal superheater 8. The saturated steam is withdrawn behind thecirculating pump 2 at I? and is conveyed through the pipe IS with theregulating valve 59 to the mixing nozzle 2b. The valve IE3 is controlledaccording to the final temperature of the useful steam by the thermostat2! (t), as indicated by the impulse pipe 22.

The final superheating oi the useful steam can also be regulated bymeans of the steam circulating pump 2 by varying he quantity of steamcirculated.

In the flow of flue gases, the course of which is indicated. by arrows,there is disposed in the usual way behind the convection-superheater 4an economiser 23 and an air heater 2%.

What I claim is:

l. A high pressure steam generator operating on the steam circulatingsystem, comprising a boiler drum, a closed circulatory system for steamacting as a heat carrier, means for withdrawing useful steam and heatcarrier steam from the boiler drum and for conveying the same throughthe circulatory system, radiation superheaters for superheating jointlythe useful steam and the heat carrier steam, means for withdrawing theuseful steam after said superheating stage, a convection superheater forfurther superheating the said heat carrier steam and means for furthersuperheating the said withdrawn useful steam separately to a temperaturewhich is higher than the final temperature of the heat carrier steam.

2. A high pressure steam generator operating on the steam circulatingsystem, comprising a boiler drum, a closed circulatory system for steamacting as a heat carrier, means for withdrawing useful steam and heatcarrier steam from the boiler drum and for conveying the same throughthe circulatory system, radiation superheaters and convectionsup'erheaters for superheating jointly the useful steam and the heatcarrier steam, means for withdrawing the useful steam after saidsuperheating stage, means for further superheating the said heat carriersteam and meansfor further superheating the said withdrawn useful steamseparately to a temperature which is higher than the final temperatureof the heat carrier steam.

3. A high pressure steam generator operating on the steam circulatingsystem, comprising a boiler drum, a closed circulatory system for steamacting as a heat carrier, means for withdrawing useful steam and heatcarrier steam from the boiler drum and for conveying the same throughfor further superheating the said withdrawn useful steam separately to atemperature which is higher than the final temperatureof the heatcarrier steam.

4. A high pressure steam generator operating on the steamcirculatingsystem, comprising a boiler drum, a closed circulatory systemfor steam acting as a heat carrier, means for withdrawing useful steamand heat carrier steam from the boiler drum and for conveying thethrough the circulatory system, a radiation and a convection superheaterfor superheating jointly the useful steam and the heat carrier steam,means forv withdrawing the useful steam after said superheating stage,means for further superheating the said withdrawn useful steamseparately to a temperature which is higher than that of the heatcarrier steam, said convection superheater being divided in two sectionsand the superheater for the final superheating of the useful steam beingarranged in the flow of the heating gases between said. two sections ofthe common convection. superheater.

5. A high pressure steam generator operating on the steam circulatingsystem, comprising a boiler drum, a closed circulatory system for steamacting as a heat carrier,means for withdrawing useful steam and heatcarrier steam from the boiler drum and for conveying the same throughthe circulatory system, a radiation and a convection superheater forsuperheating jointfor further superheating the said withdrawn usely theuseful steam and the heat carrier steam, means for withdrawing'theuseful steam after said superheating stage, means for furthersuperheating the said withdrawn useful steam'separately to a temperaturewhich is higher than that of the heat carrier steam, said convectionsuperheater being divided in two sections, the first being constructedas a unifiow superheater and the superheater for final superheating ofthe useful steam being arranged in the flow of the heating gases betweensaid two sections of the common convection superheater.

. 6. A high pressure steam generator operating 'on the steam circulatingsystem, comprising a boiler drum, a closed circulatory system for steamacting as a heat carrier, means for withdrawing useful steam and heatcarrier steam from the boiler drum and for conveying the same throughthe circulatory system, a radiation and a convection superheater forsuperh'eating jointly the useful steam and the heat carrier steam, meansfor withdrawing the useful steam after said superheating stage, meansfor further superheating the said withdrawn useful steam sep arately toa temperature WhiCh'iS higher than that of the heat carrier steam, saidconvection superheater beingdivided in two sections, thefirst sectionbeing constructed as a unifiow superheater and the second section as acounterflow superheater, the superheater for the final superheating ofthe useful steam being'arranged in the flow of the heating gases betweensaid two sectionsof the common superheateri 7. A high pressure steamgenerator operating on the steam circulating system, comprising a boilerdrum, a closed circulatory system for steam acting as a heat carrier,means for superheating jointly the useful steam and the heat carriersteam, means for withdrawing the useful steam after saidsuperheatingstage and means for further superheating' the said withdrawnuseful steam separately to a temperature which is higher than thatof'the heat carrier steam, a circulating pump for withdrawing the steamfrom the boiler drum and conveying it into thev circulatory system,means for withdrawingv saturated steam from the circulatory system atthe pressure-side of the'circulating pump, means for mixing the saidsaturated steam with the useful steam at a point,which precedes thesuperheater for the final superheating of the useful steam in thedirection of the steam flow and means for regulating the quantity of theadmixed saturated steam in predetermined relation of the degree of thefinal superheat of the useful. steam.

8. A high pressure steam generatoroperating on the steam circulatingsystem, comprising a boiler drum, a closed circulatory system for steamacting as a heat carrier, means .for withdrawing useful steam and heatcarrier steam from the boiler drum and for conveying the same throughthe circulatory system, means for superheating jointly the useful steamand the heat carrier steam, means for withdrawing the 'useful steamafter said superheating stage and means in] steam separately to atemperature which is higher than that of the heat carrier steam, aconnecting pipe for connecting the outlet end of the superheater for thefinal superheating of the useful steam with the boiler drum and ashut-off member inserted insaid connecting pipe.

'9. A high pressure steam generator operating on the steam circulatingsystem, comprising a boiler drum, a closed circulatory system for steamsteam separately to a temperature which is higher than that of the heatcarrier steam, a connecting pipe for short-circuiting the superheaterfor the final superheating of the useful steam and a shut-off memberarranged in said connecting pipe. 7

OLIVIER. SWIETOCI-IOWSKI.

